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Blog post: swansont: Messin' With Sasquatch

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Sasquatch here being wall-plug (mains) electricity

 

The initial inquiry at work was innocent enough, I think — a colleague asked what the voltage limit of a BNC connector is. Wikipedia (linking back through a vendor's spec sheet) says 500 V, and one also has to worry about the coaxial cable, which was the discussion until another colleague popped out of an office with "Two-and-a-half kiloVolts". Complete with a description of the apparatus where that appeared in the experiment.

 

That led into a discussion of some of the crazy things we had done in the lab when we occasionally (or not so occasionally) didn't have a strong grasp of what was going on. Two of the items that came up (and I had heard the story before, but it had been a few years) were The Cord of Deathâ„¢, and Son of the Cord of Deathâ„¢.

 

The Cord of Death™ sounds scary enough: it was a standard 3-prong power plug, i.e. with a ground pin (NEMA 5-15) … on both ends. Which is not advisable under almost any conditions. Apparently it was used to power a power strip whose power cord connection was bad and could not be fixed, but the rest of the strip was fine. And since all of the connections are in parallel, if you supply power to any outlet in it, the rest will have the juice. And in a grad school situation, I can see how such a kludge would be done instead of spending money on a new power strip.

 

The Son of the Cord of Death™ was a power cord, with the ground pin snipped off, and a BNC connector on the far end. I'm sure there are several applications for a connection where you want and AC signal at 60 Hz and around 120V, so why not skip the middle-man and avoid a power supply that's just going to give you what the mains is supplying (oh, safety. Well, there is that, I suppose…)

 

All reminiscent of connecting two forks or metal rods onto a power cord to cook a hot dog or make a pickle glow.

 

[youtube:http://www.youtube.com/watch?v=tMhXCG6k6oA]

 

I didn't have any contributions quite so reckless. I blew several things up in the lab in grad school — I don't think any of our laser diodes died of old age — but I stayed away from deliberately messing with wall socket electricity as much as possible.
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